Genetic and antigenic characterization of neutralizing epitopes on bluetongue virus serotype 10.

摘要

The objective of these studies was to characterize the genetic and antigenic properties of the neutralizing epitopes present on a single serotype of bluetongue virus (BTV-10). A panel of neutralizing monoclonal antibodies (MAbs) was produced to BTV-10. Four distinct neutralizing epitopes on outer capsid protein VP2 are recognized by the MAbs based on competitive immune-precipitation assays and cross-neutralization of MAb specific neutralization-escape viral variants. The epitopes are individually defined by representative MAbs 034, 039, 041 and 045. The neutralizing epitopes behave as interacting sites within a single immunogenic domain and appear to be conformationally dependent based on dsRNA and polymerase chain reaction based sequence analysis of gene 2.; A procedure for oligonucleotide fingerprint analysis of multiple BTV genes utilizing small gels was developed to investigate the genetic variability and evolutionary relationships of the BTV serotypes endemic in the United States. Results indicated that genetic reassortment has occurred often in nature and that gene segment 2 is highly conserved within serotypes and is the only serotype specific gene. In addition, fingerprint analysis indicated that BTV serotypes 10, 11, 13, and 17 have evolved together in the United States for a considerable period whereas BTV-2 appears to be a relatively recent introduction.